The present invention relates to rolled flexible sheet material dispensers. It particularly relates to those dispensers having sliding cutter rotators disposed within their feed rollers which cut a web of flexible sheet material into individual lengths of material as the web is pulled out of the dispensers, and which dispensers then feed a preselected length of the material from the dispenser accessible to the next user. It further relates to the feed roll mechanisms for such dispensers.
Many designs for dispensers for rolled flexible sheet material, such as paper toweling, are known. Examples thereof are shown in U.S. Pat. Nos. 3,575,328, Re. 28,911, 3,851,810, 4,142,431, 4,206,858, 4,404,880, 4,712,461 and 4,732,306, and copending application, Ser. No. 07/175,255, all of the present assignee. The contents of each of these patents and the '255 application are hereby incorporated by reference in their entireties.
The '461 dispenser, for example, is especially adapted for creped paper toweling where the cutting mechanism is to be actuated solely by the pulling on the paper web and usually by the user's wet hands. A straight sliding knife inside of the feed roller is mounted so that the knife blade follows a path parallel to and offset from the radius of the feed roller. A camming mechanism imparts a reciprocating movement to the blade, as the feed roller is rotated by drawing on the web of material exposed at the dispenser exit. After the blade has cut the web of material and the feed roller rotated further through its cycle the edge of the blade is retracted into the feed roller. Small uncut portions of the web are spaced across the width of the web and with only a minor decrease of pulling force applied by the user the separated uncut portions are torn and the user thereby effectively obtains the appropriate length of toweling. At the same time a free length of web material is provided available and disposed beneath the dispenser exit ready for and accessible to the next user. By exposing a lead length of towel web the next user need not, for sanitary reasons, touch any parts of the dispensers which are often located in public washrooms. Thus, a preselected length of the supply web is severed by a knife as the web is being withdrawn by the user, and a portion of the next sheet is automatically fed outside of the dispenser convenient to the next user.
A number of types of springs, both extension and torsion springs, for drivingly rotating dispenser feed rollers are known. In these known spring designs however, the spring cooperates with an eccentrically mounted pin which is connected with the feed roller, so that the spring is cocked and unloaded only once during each rotation of the feed roller.
Considerable energy is needed to sever the towel web and to automatically feed a portion of the web outside of the dispenser. Where this energy is supplied by the user as he pulls on the towel web with his wet hands, the maximum needed pull must be kept to a minimum to prevent pieces of the wet absorbent toweling from tearing off in the user's fingers. This is especially true for today's softer (less harsh) low-creped paper, such as the Cormatic "Ultima" Towels.